In the art relating to engine fuel injectors for fuel delivery to engine induction systems, the commonly used types of injectors fall into two categories. These are top feed injectors wherein fuel is fed to the injector through an opening at the upper end and bottom feed (sometimes called side feed) injectors wherein fuel is fed to the injector through side openings located near the outlet nozzle end of the injector. Because of differences in the design, as well as the manner of fuel feed, these two types of injectors have traditionally been manufactured on separate assembly lines. This requirement adds to the cost of manufacture and limits flexibility as to the amounts of different types of injectors which may be economically produced.
Recently proposed injector assembly techniques have opened the possibility of having common components between bottom feed and top feed injector designs, allowing assembly of either type of injector on the same equipment. However, because of the differences in the fuel feed arrangements for the two injector types, the necessity continues for having a separate calibration and assembly line with different forms of fuel feeding equipment.